Cam-operated pivoted-jaw clamp having plural positions for cam and jaw fulcrums



July 18, 1950 s.. R. KELLER 2,515,877

CAM-OPERATED PIVOTED-JAW CLAMP HAVING PLURAL POSITIONS DFOR CAM AND JAWFULCRUMS Filed July 14, 1947 llln'l mum I N VEN TOR.

ATTORNEYS lunmuml Patented July 18, 1950 L Spencer K. Keller, Handley,Va... assignor to Marathon Coal. Bit Company, Incorporated,

Virginia ontgomery, W. lla a corporation of West ApplicationJulyM, 1947,Serial netsaszs My present invention relates to the general class ofportable-clamps orwork holders,- and more specifically to a cam-operatedpivoted-jaw clamp having plural positions for cam and jaw fulcrums ofthe type actuated by a pivoted lever and adapted for use on the table orbench of drill presses, welding, and cutting tools, and other machinetools, as a work holder. y

The object of theinvention 'is to provide a jaw clamp which is adaptedto be'operated by a cam, the clamp serving to hold work pieces ofvarious shapes andsizes whereby an operator can use a drill press,milling, or other machine on the work piece as desired. a

.. 'lAnother object of the invention is to-provide a clamp which isextremely simple and inexpensive to manufacture. t t 1 y 1..

Other objects and advantages will beapparent during the course of thefollowing description.

In the accompanying drawings I have illustrated a complete example of aphysical embodiment of my invention in which the parts are combined andarranged in accord with one mode I have devised for the practicalapplication of the principles of my invention. It will, however, beunderstood that changes and alterations are contemplated and may be madein these exemplitying drawings and mechanical structures, within thescope of my claims, without departing from the principles of theinvention.

Figure 1 is a view in side elevation of a unitary clamping unit in whichmy invention is embodied, and shown in operative position.

Figure 2 is a top plan view of the structure in Fig. 1.

Figure 3 is a view in elevation at the workholding end of the clamp.

Figure 4 is a transverse detail sectional view at line 4-4 of Fig. 1showing the hold-down bolt for the clamp frame; and

Figure 5 is a detail sectional view at line 5-5 of Fig. l disclosing theV-shape block or work holder.

In order that the general arrangement and utility of parts may readilybe understood I have indicated a portion T of a drill press table uponwhich the appliance may be mounted for use by means of an angle bar I inwhich an attaching hole is drilled for the attaching bolt 2 that ispassed through a similar hole in the table and secured by a nut 3.

The clamp frame having a base plate 4 is mounted in horizontal positionon the angle bar I and secured thereon by a hold-down bolt 5 passedthrough registering holes drilled in the base plate 3 claims;((31.1444290) 2 1 l i and angle bar,.and the nut 6 rigidly clamps theseparts together. y v

The clamp frame includes a pair of spaced and upright forked posts Iandfl, preferablyinteg'ral with the base plate 4, and each ofthepostsis" provided witha series of vertically spaced hear; ing holes 9for selective use with the operating parts of the clamp. y

-On the upright post. 8 a rocker arm 10 having a perforated bearing lugII is mounted with a rock shaft or pin 12 passed through selected reg-Iistering holes in the lug and forked post; and an operating or cam lever13 is mounted in the spaced post 1 and provided with a camhead, l4 thatis journaled on pivot pin or shaft 15.

The angular cam lever 13 and its cam head H are proportioned, and thelever is mounted on the. pivot pin soethat when the lever is swung theright in Fig. 1 to upright idle position, the center of gravity of thelever will be at the right side of the pivot, and the clamp is released.On its operating stroke, the cam lever is turned down from uprightposition to the clamping position of Fig. 1 to hold the work W.

The lever and its cam co-act with the long arm I6 of the rocker arm,which is located just over the cam head between the forks of the post I,and a work-holding bolt I1 is adjustably mounted in the short arm I 8 ofthe rocker arm for clamping the work, as W, in the work holder.

As here shown the work holder is a V-shaped or grooved block l9,rotatably adjustable to different selected angles and provided with abottom boss 20, of cylindrical shape in cross section, that fits into acomplementary socket II of the angle bar I, and a locking bolt 22 isthreaded upwardly through the counterborcd angle bar and into thethreaded boss of the block.

To accommodate small parts, as for instance a drill D in Fig. 1, therocker arm may be equipped with an adjustable extension arm 23, thatterminates in a forked end 24 for holding the drill on the base B. Theextension arm conforms to the shape of the rocker arm, and the extensionarm may readily be attached to the rocker arm by use of the clamp boltl'l, or when not required the extension arm may with equal facility beremoved from the rocker arm. The extension may be employed in clampingsmall parts, as for instance a washer W in Fig. 1 that is to be drilledby the drill D, and the clamp may be adapted to various thicknesses ofwashers by vertically adjustin the bolt ll and/or the pivot bearings l2and l 5 for the rocker arm and lever.

In clamping work beyond the adjustment of axis to accommodate the work.

The clamping appliance thus described and illustrated is well adaptedfor use in-holding work in horizontal as well as vertical planes, upon adrill press, milling machine, a planer, or other machine tool, and amaximum lever action with the expenditure of a minimum manual force isaccomplished from the cam head and through the rocker arm and clampbolt, or through the extension, for holding down the work.

Having thus fully described my invention, what I claim as new and desireto secure by Lete E' e ti 1. In a manually operated clampingjappliance,the combination with a base having a work holder, anda clamp'framemounted on the base, of a pair of spacedupri'ght. posts rigid. with saidframe and a series. ,Qfvertically spaced bearings in' each' post, a'rocker arm pivotally mounted in a selected bearing of one post, 'aclamp bolt mounted in said arm for co-actionwith said work holder, anjoperating lever pivotallymounted in a selected bearinglofthe otherpost, and a camhead on said lever for co actior'i with said rocker arm.

.j 2. In a manually-operated clamping appliance, the combination with abase having a socket, a workholder providedwith a boss seated in saidsocket, a n attaching bolt releasably securing said boss to' said base,and a clamp frame mounted onsaid base, of a pair,of spaced upright postsrigid with said frame and a series of verticallyspaced hearings in eachpost, a rocker arm pivotally mounted in a selected bearing of one post,a clamp bolt mounted in said arm for coaction with said work holder, anoperating lever pivotally mounted in a selected bearing of the otherpost, and a cam head on said lever for coaction with said rocker arm.

3. In a manually operated clamping appliance, the combination with abase having a socket, a work holder provided with a boss seated in saidsocket, means for releasably securing said bossto said base, and a clampframe mounted on said base, of a plurality of spaced upright postsprojecting from said frame and a series of vertically spaced bearings ineach post, a rocker arm pivotally'mounted in a selected bearing of I onepost, a clamp bolt mounted in said arm for coaction with said workholder, an operating lever pivotally mounted in a selected bearing ofthe other post, and a cam head on said lever florf'co action with saidrocker arm.

SPENCER R. KELLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

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